MMP17 and gastric cancer: No significant difference was identified between the mRNA expression of MMP17 in the normal gastric and atrophic gastritis tissues (0.754±0.074 and 1.226±0.082, respectively; t=0.602; P>0.05), however, an evident difference was observed in the gastric cancer tissues (12.126±0.743; t1 8.079; t2=4.493; all P<0.05) (Fig. 2).